big brakes, why not the 2012 Stang GT

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onelapduster

onelapduster

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I spent all day yesterday reading about big brake DIY kits. Most of the kits using 13 inch rotors go with the 03/04 Cobra calipers, and a machined rotor for the hub. Those PBR calipers are tough to get without spending $400 plus. So I started researching other Stang's, '13 GT w/Brembos or '13 GT500's, these run a premium but are a gigantic 14' inches, then I came across the '12 GT, they use a slider dual piston caliper and a pleasing 13.22 rotor. Without having the parts in hand, they appear to be no different than the Cobra parts. I ran parts cost, and figured i could do this under $500, maybe cheaper depending on used or new machined down rotors for the hubs.

Yes, i know there are inexpensive kits available, but I am a DIY gear head, but also get quality parts when the research supports it. We could beat the horse on available kits, not looking to do that.

Discuss using the current generation Stang 13.22 brakes, or the Brembo/GT500 14' brakes.


To give a little info on my previous efforts, I just got done doing an LM7/4L60e swap in my 80 Firebird, did the full wiring harness, throttle by wire swap. Ive also got a 72 F100 with an '04 Mach1 engine with 5 speed swap going that also has an '07 Vic front suspension.

Im here to share the buildup of my 75 Duster.


Ready........go!!!!
 
I ran the brembo's on the front of my car for a while and loved them. it's worth the money. I think they worked a little better than my big wilwoods I have now.
 
If you're going to go that big I'd go with separate hats and rotors. Use drum brake front hubs w/o the drums (obviously) or disc brake hubs with the rotors cut off.

Radial mount and sliding calipers both present design/fab challenges to the home shop guy. Really depends on ingenuity, tools available, and skill-set. I'd be looking at ear type mounts myself, and I used to design brake kits for wilwood. An option that might be worth looking into are late model 4WD Tundra front brake parts. 2WD's are different, the 4WD's use an ear mount, fixed caliper.
 
Don't think it is really in line with what you asked, but you might look into the c5/c6 corvette calipers, too. They actually match baer brake's next level up from the cobra style caliper and are easy to source. That's what I have worked up to put on my Duster with the Cobra rotors and factory hubs created by machining the rotor off.

Can't say they are better than the GT calipers you are talking about, though.

BTW, drum hubs don't work, unless I missed something. I was unable to find a hub that had the big inner bearing to match my disk spindles, and I looked hard.
 
What are you doing with your car that you think you need brakes big enough to stop a dump truck?
 
RustyRatRod said:
What are you doing with your car that you think you need brakes big enough to stop a dump truck?
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Obviously the same stuff as the people who designed the factory Mustang GT... Stop really quick from high speed ;)

I know I'm gonna want bigger than the factory '73-up rotors and calipers once I start doing any real road racing with high speeds.
 
RustyRatRod said:
What are you doing with your car that you think you need brakes big enough to stop a dump truck?
Click to expand...

I want to be able to say "I have 13 inch brakes" of course. My goal is to modernize my Duster. I am looking to autocross and do open track days. Plus, my car is nothing special as a stock car and no one will care if I use it in a demo derby or put an LS engine in it. I've had this car for the better part of 18 years, tore it down 10 years ago and life got me side tracked. So here I am.

The C5 and C6 caliper and brakes are a common upgrade on the 2nd gen f bodies. I was looking at these calipers as an option as well.
 
The size of brakes has to be proportional to the tire patch you can put on the ground. Well, it doesn't have to be, but.....most abodies have limited wheel wells.
I do like the big brakes on my S6 though so you have me thinkin'
 
once the brakes are strong enough to lock the wheels, the only thing that affects stopping distance is the quality of the rubber ;)

so a car with 10" or 11" or 40" rotors they will all stop the same distance depending on the tires

so the real thing you should remember is that if going bigger rotors means you have to use narrower wheels that's a bad idea.
 
Nearly any drum brake can lock the tire up. It is a common misconception that once the brake is strong enough to do that then you're done - it can't get any better.

At their most basic description brakes turn Kinetic Energy in to Heat. The better that they are at dumping the heat into the air, the better their stopping power. That is why discs out-stop drums. They don't necessarily have more braking torque. It is that they are much better at dumping the heat that they generate into the air.

Can think of rotor diameter as being directly related to braking torque, and rotor width as directly related to heat rejection ability.

Can not ignore vehicle dynamics when considering braking force, and that plays a big part in braking traction.

If the tires are locking up, then the driver isn't doing his/her job.
 
I won't bother with those brakes, in my opinion they don't work any better than the 12" Mopar cordoba brakes with good pads.
 
I have stock manual disks in front, explorer rear disks and will say that although they will lock up the 245's in the front, they get blue from even the slightest spirited driving and I'm guessing will suffer a nuclear meltdown during an autocross.
Repeatable stopping power is needed and I think this is where we're going with this thread. With bigger rims and tires, we're overrunning the capabilities of the stock disks to perform well repeatedly.
I'd trust my brakes at the drag strip and in normal traffic, but not at the autocross.

I'm interested to see where the conversation goes as I'll be looking for a solution soon as well.
 
ntsqd said:
Nearly any drum brake can lock the tire up. It is a common misconception that once the brake is strong enough to do that then you're done - it can't get any better.

At their most basic description brakes turn Kinetic Energy in to Heat. The better that they are at dumping the heat into the air, the better their stopping power. That is why discs out-stop drums. They don't necessarily have more braking torque. It is that they are much better at dumping the heat that they generate into the air.

Can think of rotor diameter as being directly related to braking torque, and rotor width as directly related to heat rejection ability.

Can not ignore vehicle dynamics when considering braking force, and that plays a big part in braking traction.

If the tires are locking up, then the driver isn't doing his/her job.
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Yes^^^

Other considerations are if tires are locking up, maybe there's too much weight transfer from the aft, or too much braking to the back compared to the front.
 
although they will lock up the 245's in the front, they get blue from even the slightest spirited driving and I'm guessing will suffer a nuclear meltdown during an autocross
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Ouch! If they're getting that warm, you either need lay off the brakes or get a different rotor
 
:wack:
so the real thing you should remember is that if going bigger rotors means you have to use narrower wheels that's a bad idea.[/QUOTE]

I have run stock disk/drum and now the big brakes in two versions,there is a big difference. tires do make a big difference to go along with them,but big brakes rock. the first time I road tracked my car with the big front wilwoods I glazed the pads. bill reilly had them send me upgraded pads and they are fine now. one trip around the track and I would change you guys mind.
 
txstang84 said:
Ouch! If they're getting that warm, you either need lay off the brakes or get a different rotor
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Yep, Now that the Duster has the 360 in it, it needs some help.
I'm really talking about 5-6 hard stops on a trip to work on the weekend. The corporate plaza has some nice twisty roads and no cars to speak of on a Saturday morning :)
I'll most likely do the 11.75 rotor upgrade. It doesn't need too much help, but since it'll be a daily driver in the next couple of months I'd like to know the brakes aren't glazed when some jackamo pulls out in front of me.
 
player1up said:
Yep, Now that the Duster has the 360 in it, it needs some help.
I'm really talking about 5-6 hard stops on a trip to work on the weekend. The corporate plaza has some nice twisty roads and no cars to speak of on a Saturday morning :)
I'll most likely do the 11.75 rotor upgrade. It doesn't need too much help, but since it'll be a daily driver in the next couple of months I'd like to know the brakes aren't glazed when some jackamo pulls out in front of me.
Click to expand...

Do the 11.75 inch swap with good pads like the ones firm feel sells, I don't think you will see any improvement by going to the Mustang GT brakes.
 
Bigger brakes are all about heat dissipation predominantly. If you cant increase diameter because of wheel size then increase thickness, look at the short track package of a Nascar they are THICK like 1.5" or bigger.
 
player1up said:
I have stock manual disks in front, explorer rear disks and will say that although they will lock up the 245's in the front, they get blue from even the slightest spirited driving and I'm guessing will suffer a nuclear meltdown during an autocross.
Repeatable stopping power is needed and I think this is where we're going with this thread. With bigger rims and tires, we're overrunning the capabilities of the stock disks to perform well repeatedly.
I'd trust my brakes at the drag strip and in normal traffic, but not at the autocross.

I'm interested to see where the conversation goes as I'll be looking for a solution soon as well.
Click to expand...

Sounds to me you need better pads!
 
72BBSwinger said:
Bigger brakes are all about heat dissipation predominantly. If you cant increase diameter because of wheel size then increase thickness, look at the short track package of a Nascar they are THICK like 1.5" or bigger.
Click to expand...
Have to disagree. No doubt that heat dissipation increases with a larger OD, but a larger rotor diameter is about more brake torque. Brake torque is a function of the radial distance from rotational axis to the centroid of the brake pad's contact area. Increasing that by going to a larger OD rotor (& moving the caliper further out as appropriate) means more torque, all other things being equal.
A thicker rotor will usually have bigger vents between the friction surfaces, so they can pump more air thru themselves and that is huge towards heat dissipation.
 
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